GB2131260A

GB2131260A - Integral heat pipe-electrode

Info

Publication number: GB2131260A
Application number: GB08332004A
Authority: GB
Inventors: Daniel Joseph Racki
Original assignee: Westinghouse Electric Corp
Current assignee: Westinghouse Electric Corp
Priority date: 1982-12-02
Filing date: 1983-11-30
Publication date: 1984-06-13
Also published as: NO834348L; CA1215096A; JPS59105286A; NO157680C; FR2537375B1; GB2131260B; IT8323735A0; IT1168712B; NO157680B; US4477911A; DE3341156A1; AU2062583A; AU556942B2; GB8332004D0; FR2537375A1; ES8507307A1; ES527581A0

Description

1 GB 2 131 260 A 1

SPECIFICATION

Integral heat pipe-electrode Th is invention relates to electrodes used to heat molten metal material especially a bath of molten metal or glass. Such electrodes usua 1 ly extend into a container having a volume of molten material or material to be melted, and penetrate belowthe surface of the molten pool. The electrode is used to supply electrical energy to the molten orto be melted material.

The extremely large amount of heat generated in the electrode requires an elaborate cooling system.

Commonly, a heat pipe is coaxially incorporated within the electrode. The operational principles of a heat pipe are well known and are described in variuos sources including U.S. Patent Nos. 3,865,184 and 3,753,364. Briefly stated, a heat pipe is a tube providing a thermosiphon of vaporization constituted 85 by a reservoir of good heat conducting quality, forming a closed circuitthe interiorwall of which is lined with a metallic mesh constituting a capillary structure. One end of the heat pipe is heated and the other end is cooled. Within the heat pipe, a continuous cycle of evaporation-condensation occurs. transferring heat axially toward the coolerend. Tne installation of such a heat pipe into a electrode is difficult and relatively expensive and sometimes the cause for problems during operation of the electrode.

It is therefore the principal object of the present invention to provide an electrode with a heat pipe incorporated therein which is simple, easily manufactured and reliable in operation.

With this object in view,the present invention resides in an electrode forconducting electrical energyto a molten material bath having heat pipe meansforcooling said electrode, comprising an electrode body of copper, adapted to extend into said bath, said body having an axial hole extending into it from a first end thereof, characterized in that a coating is applied overthe copper body surfaces defining said hole, which coating protects the copperfrom interaction with a volume of high temperature heat pipe fluid disposed within and at the other end of said hole when 110 said electrode is in operating position, and that cooling means are arranged atthe first end of said electrode body for the removal of heat carried by said fluid from the otherto said first end of said body thereby to cool the other end of said electrode.

The invention will become more readily apparent from thefollowing description of a preferred embodimentthereof shown, by way of example only, in the accompanying drawings, wherein:

Figure 1 is a longitudinal sectional view of a prior art electrode; and

Figure 2 is a longitudinal sectional viewof an electrode of a first embodiment.

Figure 1 represents the state-of-the-art electrodes.

Electrode 1 extends into a container 10 holding a bath 2 of molten aluminium. Typically, electrode 1 is an eightfoot long copper cylinder of one foot diameter. A two inch diameter heat pipe 3, seven feet long, is shrunkfit into a hole bored into the electrode. Plenum 4 contains a substance, usually potassium or mercury which is the heat transfer medium. The upper end of the electrode has a water cooling jacket system 5. Figure 1 also shows a portion of the mesh 6 which is the capillary system of the heat pipe. Arrows 7 illustrate heatflow.

Figure2 illustrates a first embodiment of an improved integral heatpipe electrode. Items 1, 2,4,5, 6,7 and 10 are identicalto Figure 1, butcomponent3, a pipewhich is part ofthe heat pipe system of Figure 1 is omitted.The plenum 4formed by atwo inch bored hole in the electrode itself is used as the heat "pipe". The inner surfaces of the bored hole is coated with a 30 mil layer of molybdenum, nickel, or stainless steel, by vapor deposition to protectthe copper of the electrode

Claims

from interaction with the mercury or potassium fluid in the plenum 4. This protective coating is represented by a dotted line 8 in Figure 2. Figure 2 also shows a seal plug 11 and an access plug 12 to plenum 4. CLAIMS

1. An electrode for conducting electrical energy to a molten material bath having heat pipe means for cooling said electrode, comprising an electrode body (1) of copper, adapted to extend into said bath (2), said body (1) having an axial hole extending into itfrom a first end thereof, characterized in that a coating is applied overthe copper body surfaces defining said hole, which coating protects the copperfrom interaction with a volume of high temperature heat pipe fluid disposed within and atthe other end of said hole when said electrode is in operating position, and that cooling means (5) are arranged atthe first end of said electrode body (1) forthe removal of heat carried by said fluid from the otherto said first end of said body therebyto cool the other end of said electrode.

2. An electrode as claimed in claim 1 characterized in that said coating is nickel.

3. An electrode as claimed in claim 1, characterized in that said coating is stainless steel.

4. An electrode as claimed in claim 1,characte- rized in that said coating is molybdenum.

5. An electrode asclaimed in anyof claims 1 to4 characterized in that said fluid is potassium.

6. An electrode as claimed in anyof claims 1 to 5 characterized in that said bath is aluminum.

7. An electrode as claimed in anyof claims 1 to 5 characterized in that said bath is glass.

Printed for Her Majesty's Stationery Office byTheTweeddale Press Ltd., Berwick-upon-Tweed, 1984. Published atthe Patent Office, 25 Southampton Buildings, London WC2A lAY, from which copies may be obtained.